This book by James Webb is getting a lot of attention in the conservative/libertarian blogosphere.  Webb recently wrote an OpEd for WSJ which captures some of the key themes of the book -

...Why are the 30 million Scots-Irish, who may well be America's strongest cultural force, so invisible to America's intellectual elites? It is commonplace for commentators to lump together those who are descended from British roots into the WASP culture typified by New England Brahmins, or the Irish, who are overwhelmingly Catholic. But it is political nonsense to consider the Scots-Irish as part of either.

The Scots-Irish are derived from a mass migration from Northern Ireland in the 1700s, when the Calvinist "Ulster Scots" decided they'd had enough of fighting Anglican England's battles against Irish Catholics. One group settled initially in New Hampshire, spilling over into modern-day Vermont and Maine. The overwhelming majority--95%--migrated to the Appalachians in a series of frontier communities that stretched from Pennsylvania to northern Alabama and Georgia. They eventually became the dominant culture of the South and much of the Midwest.

True American-style democracy had its origins in this culture. Its values emanated from the Scottish Kirk, which had thrown out the top-down hierarchy of the Catholic Church and replaced it with governing councils made up of ordinary citizens...

...Matched with this rebelliousness was a network of extended family "clans," still evident among the Scots-Irish, built on an egalitarianism that measured a person by their own code of honor, courage, loyalty and audacious leadership. Noted Scottish professor T.C. Smout said it best when he observed that these relationships were "compounded both of egalitarian and patriarchal features, full of respect for birth while being free from humility." They demanded strong leaders, but would never tolerate one who considered himself above his fellows. Andrew Jackson, the first president of Scots-Irish descent, forever changed the style of American politics, creating a movement that even today is characterized as Jacksonian democracy.

Having some affinity for Texas, I particularly liked this review in NRO which focused on the heart / soul of country music and the Scots-Irish -

It is no accident that Webb describes the importance of country music for the Scots-Irish in his chapter entitled "Fight. Sing. Drink. Pray." Country music is about real life, about "hard living, cheating hearts, and good-looking women." It's also about sin and redemption. Country music teaches that actions have consequences, and no one has ever conveyed this reality more clearly than the hard-living, hard-drinking George Jones. The titles of his songs tell it all: "From Hillbilly Heaven to Honky-Tonk Hell," "Hell Stays Open All Night Long," "The Man that You Once Knew," "He Stopped Loving Her Today," and "I've Had Choices."

Reminds me of my Ode to Texas. 

More recently, I can't help but wonder if perhaps the Scots-Irish were the original sheepdogs?  Or at least the original culture in America which deeply revered them - the military tradition amongst the Scots-Irish - would strongly correlate with this.  My vote for one of the biggest Scots-Irish in the blogosphere would go to Kim DuToit (philosophically, not ethnically).